Narrow Results

The ideas underpinning a technique of using nonlinear approximations to control chaotic dynamical systems are shown to be useful as a basis for the development of effective methods for targeting these systems. The inverses of the maps under consideration are not required. The methods are applied to the Hénon and Ikeda maps and also to an Ikeda-like map.

In this paper a process targeting model for three class screening problem is developed. The model developed, extends the work in the literature by incorporating product uniformity. The product uniformity is introduced via a Taguchi type quadratic loss function. Two cases for the process Targeting are considered. In addition, an illustrative example is presented. Sensitivity analysis is also conducted to study the effect of model parameters on expected profit and optimal process mean.

This case presents the dilemma of the decision maker in selecting the most appropriate market segment for Vanraj 10 HP mini-tractors — an innovation from a small farmer in Gujarat, India. Four market segments were identified: small and marginal farmers, large farmers, industries, and horticulture farmers. Vanraj was economical and possessed all the features of a big tractor. Mr. Trivedi, the decision maker, believed that the tractor would serve the needs of small and marginal farmers better, but his colleagues wanted him to think further before selecting any particular market segment for targeting. This case is useful for exploring segmentation and targeting decisions in marketing.

Surgical excision, radiation therapy and chemical therapy are the main treatments of hepatic carcinoma. Due to good targeting property, controlled drug release and little side-effects, targeting drug delivery system (TDDS) has become the research focus in the field of oncology therapy. This paper established numerical models of hepatic portal bifurcate branches, carried out a comparative study of hemodynamics and drug concentration distribution in the portal vein vessels for different targeted drug releasing positions. The results showed that (1) because of the influence of flow field, the drug concentration in the right branch declines 10% compared with that in the left and main branches, it demonstrated that the drug concentration in the right side of liver was obviously lower than that in the left side; There is the difference of drug concentration between the inside and the outside in both left and right branches, but it is more obvious difference in the right branch than that in the left one. (2) The drug concentration on the inside of the right branch is significantly lower than that of the other regions, it is important to consider drug use on this position. (3) The drug concentration in portal vein bifurcation is proportional to the initial release positions, at the same time the drug release time and the drug diffusion in tissue should be taken into account in order to achieve the best therapeutic effect. So a reasonable initial drug release position is determined according to physiological characteristics and drug release curves of patients.

Technetium and Rhenium are the two lower elements in the manganese triad. Whereas rhenium is known as an important part of high resistance alloys, technetium is mostly known as a cumbersome product of nuclear fission. It is less known that its metastable isotope ^99mTc is of utmost importance in nuclear medicine diagnosis. The technical application of elemental rhenium is currently complemented by investigations of its isotope ¹⁸⁸Re, which could play a central role in the future for internal, targeted radiotherapy. This article will briefly describe the basic principles behind diagnostic methods with radionuclides for molecular imaging, review the ^99mTc-based radiopharmaceuticals currently in clinical routine and focus on the chemical challenges and current developments towards improved, radiolabeled compounds for diagnosis and therapy in nuclear medicine.

Porphyrins and phthalocyanines are photosensitizers (PS) that are used in clinical imaging, detection of cancer cells and are particularly applied in photodynamic therapy (PDT). Many scientists have been focused on the design of different porphyrin compounds. However, similar to other anti-cancer agents, they cannot selectively recognize tumor tissues. Scientists are seeking new methods to overcome this problem and to find appropriate targeted delivery strategies. Plant lectins are especially suitable molecules for such targeting as they preferentially recognize specific antigens on the glycosylated cancer cells. This review will give more detailed information about the dual function of lectins and their interactions with PSs, which is a new perspective in targeted PDT. The implications and potential applications of such studies will also be discussed.

Although photodynamic therapy has been extensively studied in recent years and preclinical studies have shown promising results, strategies for enhancing PDT outcomes and reducing side effects still urgently need to be developed. In this study, a series of Tamoxifen-zinc(II) phthalocyanine conjugates have been designed and synthesized. In these “double-headed” conjugates, photodynamic therapy agent zinc(II) phthalocyanine and hormone therapy drug Tamoxifen were combined via oligoethylene glycol linkers. The conjugates show high specificity, and some of them show cytotoxic effects against the MCF-7 cells overexpressed Estrogen receptor, due to the targeting and cytostatic Tamoxifen moiety. Upon illumination, all these conjugates show high cytotoxicity due to the photosensitizing phthalocyanine unit. Their structure-activity relationship was also assessed. The results show that $\alpha$-substituted Tamoxifen-zinc(II) phthalocyanine conjugates are highly promising anticancer targeting agents which exhibit additive effects of photodynamic therapy and hormone therapy.

Porphyrins and phthalocyanines are photosensitizers (PS) that are used in clinical imaging, detection of cancer cells and are particularly applied in photodynamic therapy (PDT). Many scientists have been focused on the design of different porphyrin compounds. However, similar to other anti-cancer agents, they cannot selectively recognize tumor tissues. Scientists are seeking new methods to overcome this problem and to find appropriate targeted delivery strategies. Plant lectins are especially suitable molecules for such targeting as they preferentially recognize specific antigens on the glycosylated cancer cells. This review will give more detailed information about the dual function of lectins and their interactions with PSs, which is a new perspective in targeted PDT. The implications and potential applications of such studies will also be discussed.

This article discusses the role of the protein corona in delivery systems with tagged nanoparticles and how knowledge of the protein corona can help in optimizing delivery. The basic question is whether and how the binding of proteins and other biomolecules at the nanoparticle surface interfere with the interaction between a tag and its receptor. This is an interesting problem in many respects, but most intriguing are the observed differences in delivery efficiency in vivo compared with protein-free in vitro conditions. In order to understand possible situations that the nanoparticle will face in a protein-rich biological environment, we will first describe the formation of a protein corona and thereafter discuss potential perturbations of the delivery systems when moving from in vitro testing to in vivo applications. We emphasize the role of mathematical modeling in optimizing the design of functionalized nanoparticles to achieve high success of delivery.